Energy-shaping Controller for Time-invariant Multiple Contacts

While in the past industrial robots were strictly separated from humans, today robots serve humans in a variety of industrial applications that also involve close or even physical human-robot interaction. Hereby, safety is of utmost importance and thus, the design of the control system needs to ensure a stable and safe operation. In this context, safety has been mainly addressed for single interaction points. In this article, we present an energy shaping controller that is capable of ensuring safety even in the case of multiple human contact points that may occur when co-manipulating an object. The presented approach is tested and validated in experiments. Results indicate that for the studied co-manipulation task involving time-invariant multiple human contacts, a safe interaction can be achieved.